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libvirt/build-aux/Makefile.nonreentrant
Michal Privoznik cfcbba4c2b lib: Replace qsort() with g_qsort_with_data()
While glibc provides qsort(), which usually is just a mergesort,
until sorting arrays so huge that temporary array used by
mergesort would not fit into physical memory (which in our case
is never), we are not guaranteed it'll use mergesort. The
advantage of mergesort is clear - it's stable. IOW, if we have an
array of values parsed from XML, qsort() it and produce some
output based on those values, we can then compare the output with
some expected output, line by line.

But with newer glibc this is all history. After [1], qsort() is
no longer mergesort but introsort instead, which is not stable.
This is suboptimal, because in some cases we want to preserve
order of equal items. For instance, in ebiptablesApplyNewRules(),
nwfilter rules are sorted by their priority. But if two rules
have the same priority, we want to keep them in the order they
appear in the XML. Since it's hard/needless work to identify
places where stable or unstable sorting is needed, let's just
play it safe and use stable sorting everywhere.

Fortunately, glib provides g_qsort_with_data() which indeed
implement mergesort and it's a drop in replacement for qsort(),
almost. It accepts fifth argument (pointer to opaque data), that
is passed to comparator function, which then accepts three
arguments.

We have to keep one occurance of qsort() though - in NSS module
which deliberately does not link with glib.

1: https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=03bf8357e8291857a435afcc3048e0b697b6cc04
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
2023-11-24 09:53:14 +01:00

128 lines
3.8 KiB
Makefile

## Copyright (C) 2009-2010, 2013 Red Hat, Inc.
##
## This library is free software; you can redistribute it and/or
## modify it under the terms of the GNU Lesser General Public
## License as published by the Free Software Foundation; either
## version 2.1 of the License, or (at your option) any later version.
##
## This library is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
## Lesser General Public License for more details.
##
## You should have received a copy of the GNU Lesser General Public
## License along with this library. If not, see
## <http://www.gnu.org/licenses/>.
#
# Generated by running the following on current Gentoo:
#
# nm -D --defined-only --without-symbol-versions /lib64/libc.so.6 \
# | grep '_r$' \
# | awk '{print $3}' \
# | grep -v -e '^_' -e 'readdir' \
# | sort -u \
# | sed -s 's/_r$//'
#
# readdir*() is safe as long as each DIR * instance is only used by one thread.
#
# Also manually add in all inet_* functions some of which
# are not threadsafe and do not have _r variants. They are
# all deprecated in favour of getnameinfo/getaddrinfo
#
NON_REENTRANT =
NON_REENTRANT += asctime
NON_REENTRANT += ctime
NON_REENTRANT += drand48
NON_REENTRANT += ecvt
NON_REENTRANT += erand48
NON_REENTRANT += ether_aton
NON_REENTRANT += ether_ntoa
NON_REENTRANT += fcvt
NON_REENTRANT += fgetgrent
NON_REENTRANT += fgetpwent
NON_REENTRANT += fgetsgent
NON_REENTRANT += fgetspent
NON_REENTRANT += getaliasbyname
NON_REENTRANT += getaliasent
NON_REENTRANT += getdate
NON_REENTRANT += getgrent
NON_REENTRANT += getgrgid
NON_REENTRANT += getgrnam
NON_REENTRANT += gethostbyaddr
NON_REENTRANT += gethostbyname2
NON_REENTRANT += gethostbyname
NON_REENTRANT += gethostent
NON_REENTRANT += getlogin
NON_REENTRANT += getmntent
NON_REENTRANT += getnetbyaddr
NON_REENTRANT += getnetbyname
NON_REENTRANT += getnetent
NON_REENTRANT += getnetgrent
NON_REENTRANT += getprotobyname
NON_REENTRANT += getprotobynumber
NON_REENTRANT += getprotoent
NON_REENTRANT += getpwent
NON_REENTRANT += getpwnam
NON_REENTRANT += getpwuid
NON_REENTRANT += getrpcbyname
NON_REENTRANT += getrpcbynumber
NON_REENTRANT += getrpcent
NON_REENTRANT += getservbyname
NON_REENTRANT += getservbyport
NON_REENTRANT += getservent
NON_REENTRANT += getsgent
NON_REENTRANT += getsgnam
NON_REENTRANT += getspent
NON_REENTRANT += getspnam
NON_REENTRANT += getutent
NON_REENTRANT += getutid
NON_REENTRANT += getutline
NON_REENTRANT += gmtime
NON_REENTRANT += hcreate
NON_REENTRANT += hdestroy
NON_REENTRANT += hsearch
NON_REENTRANT += initstate
NON_REENTRANT += jrand48
NON_REENTRANT += lcong48
NON_REENTRANT += localtime
NON_REENTRANT += lrand48
NON_REENTRANT += mrand48
NON_REENTRANT += nrand48
NON_REENTRANT += ptsname
NON_REENTRANT += qecvt
NON_REENTRANT += qfcvt
NON_REENTRANT += rand
NON_REENTRANT += random
NON_REENTRANT += seed48
NON_REENTRANT += setstate
NON_REENTRANT += sgetsgent
NON_REENTRANT += sgetspent
NON_REENTRANT += srand48
NON_REENTRANT += srandom
NON_REENTRANT += strerror
NON_REENTRANT += strtok
NON_REENTRANT += tmpnam
NON_REENTRANT += ttyname
NON_REENTRANT += twalk
NON_REENTRANT += inet_addr
NON_REENTRANT += inet_aton
NON_REENTRANT += inet_lnaof
NON_REENTRANT += inet_makeaddr
NON_REENTRANT += inet_netof
NON_REENTRANT += inet_network
NON_REENTRANT += inet_nsap_addr
NON_REENTRANT += inet_nsap_ntoa
NON_REENTRANT += inet_ntoa
NON_REENTRANT += inet_ntop
NON_REENTRANT += inet_pton
# Separate two nothings by space to get one space in a variable
space =
space +=
# The space needs to be in a variable otherwise it would be ignored.
# And there must be no spaces around the commas because they would
# not be ignored, logically.
NON_REENTRANT_RE=$(subst $(space),|,$(NON_REENTRANT))